by Richard Mounce, DDS
For more on this topic, go to www.dentaleconomics.com and search using the following key words: obturation, master apical taper, Dr. Richard Mounce, The Endo File.
Part I of this two-part series began to address the question of how many obturation systems general dental clinicians might need at their disposal at any given time, and other related questions.
If the considerations in Part 1 of this two-part series are taken into account, the clinician generally should have, at a minimum, two, possibly three favored obturation techniques. In addition, these techniques should be adaptable as needed to a clinical situation that requires it.
My two favored obturation techniques are System B and the use of RealSeal* 1 Bonded Obturators. When would I use one technique over another, and why these two?
Some canal anatomies may make one technique slightly more efficient than another. For example, inserting an obturator for a right-handed clinician into the mesiolingual canal of a lower left molar can be challenging if the root is 25 mm long and highly curved, especially if the canal system is C shaped.
This challenge notwithstanding, it may be possible to use an obturator to a very high standard in such a case, but in any event, relying on one technique exclusively invites a lack of flexibility and will bring compromise in certain cases.
Minor technique nuances and adjustments may need to be made depending on the particular clinical situation. For example, in the case of a blocked apex during re-treatment, the best option might be to use the Elements Obturation Unit* and cartridges of RealSeal to fill the canal in a "squirt" technique that does not use a master cone. Caution and clinical judgment are advised.
What is critical to this flexibility in moving from one obturation technique to another is the value of practice in extracted teeth. This allows the clinician to fully understand the strengths and limitations of any given method of obturation through diligent practice with the technique.
For example, obturating several dozen extracted molars that have been made patent and instrumented with the clinician's rotary nickel titanium system can go far toward minimizing possible iatrogenic issues or shortcomings when used on live patients.
These recommendations aside, I am not an advocate of single cone cold obturation techniques. While the simplicity of this method might appeal to some, no literature claims this method is superior, and also the use of single cold master cones inserted to true working length relies entirely on a single cone to provide the hydraulic force needed to move sealer into all of the ramifications of the root canal space. This is hopeful and not predictable.
The technique also relies on large amounts of sealer that is soluble unless a resin-based sealer is used. There is no substitute for visualizing the master cone being either down packed with a vertical obturation technique such as System B or the vertical compaction technique. Inherent in this statement is the vital importance of obtaining tugback with the master cone and using the appropriate heat tips correctly. Obturator insertion is also made much more efficient using magnification and visualization.
One or two visits?
In Part 1 of this two-part series, the question was whether one or two visit treatment affected the obturation technique that might be used. The answer is no. Whether treatment is accomplished in one visit or two, the decision as to which technique would be used is independent of the number of visits.
If the tooth is asymptomatic, the patient is not swollen, canal taper and master apical diameter are ideal, the apex is clean and dry, there is no apical palpation sensitivity or percussion sensitivity, or it is a vital or nonvital case (with or without a lesion), the tooth can be obturated. In the above scenario, if the clinician wishes to obturate the canal in one visit, it is clinically acceptable to do so, irrespective of the technique used.
Finally, in some cases, there will be canals within the same tooth in which the clinician may wish to use different methods. For example, it is my preference to use System B in the MB1 and MB2 of upper molars, and use RealSeal 1 Bonded Obturators in the DB and Palatal, especially if the MB1 and MB2 join and exit from a common foramen. In my hands, using master cones in this anatomical entity is more predictable. That said, RealSeal 1 Bonded Obturators can certainly be used in this anatomical entity. I welcome your feedback.
*SybronEndo (Orange, Calif.)
Dr. Mounce is the author of the nonfiction book Dead Stuck, "one man's stories of adventure, parenting, and marriage told without heaping platitudes of political correctness," available at Pacific Sky Publishing or DeadStuck.com. Dr. Mounce lectures globally and is widely published. He is in private practice in endodontics in Vancouver, Wash.